Electric heating machine



March 31. 1925. 1,531,516

- L. SIMMONS ELECTRIC HEATING MACHINE Filed Oct. 4, 1923 Patented Mar.31, 1925.

UNITED STATES LEO SIMMONS, OF WASHIIII'GTON, DISTRICT OF COLUMBIA.

ELEC/IRIC HEATING MACHINE.

Application me October 4, 1923. Serial No. 666,552.

To all whom it may concern:

Be it known that I, 'Lro SIMMONS, a citizen of the United States ofAmerica, and resident of Washington, District. of Columbia, haveinvented certain new and a useful Improvements in and Relating to.heated in an improved manner b Electric Heating Machines, of which thefollowing is a specification.

This invention relates to improved mean for economically and effectivelyheating space for human habitation by forced.cir-

culation of the. air in said space through a heated air draft tunnel forthe purpose of raising the temperature of the air in said space to adegree that will render such space comfortable for human occupation; andthe objects and nature of the invention will be readily understood bythose skilled in the art in the light of the following explanations andthe accompanying drawings that illustrate what I now believe to be thepreferred mechanical expression or embodiment of my invention from amongother forms, constructions and arrangements within the spirit and scopethereof. a An object. of the invention is to provide improved means forraisin the temperature of the air in enclosures or human occupancybycirculating the air'within such enclosure, through an air draft tunnelelectric glow heating resistance protecte against direct contact with.the air blast passing through such tunnel.

With this and other objects in view, my invention consists in certainnovel features in construction or in combinations and arrangements asmore fully andparticularly set forth and specified hereinafter.

Referring to the accompanying draw- 1ngsz- Fig. l showsan embodiment ofmy invention in longitudinal vertical section.

Fig. 2 is a front end elevation, dotted lines indicating the enclosedprotected heating coil.

Fig. 3 is a detail longitudinal section on an enlarged scale.

Fig. 4 is a detail section on the line H,

In the particular embodiment of my invention illustrated by the drawingsas an example for purposes of. explanation, I provide an elongatedair'heatin and hot air circulating tunnel formed day elongated tubularvcasing or housing 1, open at both month or bell 1. In this instance, theenlargement in diameter is abrupt to form the annular forwardly facingshoulder or seat 1 within the air draft and heating tunnel.

The means for heating the bore of or chamber formed by the air drafttunnel, is annular in form and usually concentrically arranged withinthe enlarged front end of the tunnel in advance of the annular shoulder1, to surround and-lieat the tunnel bore and consequently heat the aircirculating through the tunnel;

For instance, the particular heating means shown consists of an annularelectric heating or resistance wire coil 2 passing through and supportedby an annular series of spaced porcelain or other insulating materialblocks or tubes 3,"with the heating coil and blocks 3 enclosed within anannular chamber a. surrounding and concentric with.

the tunnel bore and, in the example shown, formed by a hollowthick-walled heat conducting and radiating casing or coil enclosing.ring or annulus 4, fitted within the tunnel and at its otherwise outeropen side,

closed by the surrounding tunnel wall. I

This ring can be approximately U-shape in cross section on a radius,Fig. 3, and' formed with flanges 4, 4, through whichthe ring can besecured, as'by bolts 5, to the casing or tunnel walls, sothat thesurrounding outer open side or circumference of the casing or coilenclosing ring Wlll. be closed by the surroundin portion of the tunnelincreasing the heating efficiency and capacity of the tunnel.

The internal diameter of the rear end of the ring bore is, preferably,less than the inner annular portion 4 of the rear end wall of saidcasing ring forming an inwardly projecting annular shoulder or bafi'lewithin the tunnel at the front end of tunnel portion 1. This baflle 4,is, preferably, flared inwardly and forwardly to meet the rear end ofthe forwardly flared bore of the casing ring.

In the example shown, the lnsulation blocks or tubes 3, are securedinany suitable manner, as by clamps 3, within the ring, say within therear end thereof against the inner surfaces of ring walls 4, 4, and theheating coil. 2 is supported by said blocks spaced from and out ofcontact with the ring walls. The coil 2 is preferably in the form of anapn'oximate annulus encircling the interior 0 the ring with its leadingin or feed connection 2 extending to the exterior of the casing ortunnel through insulating tube 2", preferably at the underside of thetunnel casing. The annular front end wall 4 of the casing ring ispreferably formed with an annular series of spaced mica-covered openings4, through which the red glow of the coil 2 can be seen through the openfront end of the tunnel, for purposes of ornamentation. The

portions of the electric heating coil 2 intervening between theinsulation supporting blocks 3, are exposed within the ring chamber a,but are cut off by the casing ring and the mica-covering the ringopenin-gs, from being directly contacted by the air blast or circulationthrough theair tunnel, as it is the pin-pose of my invention to keep theelectric heating element or elements 2, at a constant high temperatureand red heat or glow while in action, to maintain the coil-casing metalring 4 at the desired high temperature byradiation, convection,conduction through the insulation blocks 3 and by maintaining a hightem- The object is to perature in chamber (a. prevent cooling the coilby exposlng the 'same to direct contact with the air circulation, and toutilize the high temperature, red heat, ofthe coil tofmaintain a hlghertemperature of the extensive radlatlng surfaces of the casing ringexposed within the tunnel and to thereby heat the cham ber constitutingthe tunnel-bore, and to confine the heat within the tunnel bore as opposed to the exterior surface of the tunnel casing. To this end thetunnel casing can be composed of inner and outer shells and interposedasbestos insulating packing, or

the casing is otherwise insulated or is com is preferably composed of amore or less thick walled metal casting, that will hold or carry theheat, and I find aluminum well suited for the purpose, whereby the airdriven through the tunnel is most effectively and economically heated bycontact with and by the heat radiation from the throat formed within thetunnel by the metal coil casing ring.

An electric motor driven blower is provided to rapidly force thecircuation of the air of the living space to be heated through theheated tunnel and into contact with hot surfaces and through the zone ofheat radiation for the purpose of raising the temperature within saidspace to the desired degree and thus maintaining the same. For thispurpose, I provide rotary air blast or blower 6, within the rear end ofthe tunnel with its axis alined with the longitudinal tunnel axis. Thisblower is carried and driven by electric motor 7 removably fixed and suported within the rear end of the tunnel by any suitable means. Forinstance, I show the motor tightly clamped between the middle portionsof apair of clamp bars or brackets 8, by clamping bolts 9 arranged aboveand below the motor andextendlng transversely through the bars, wherebythe middle portions of the bars can be drawn toward each other orallowed to spring away from the motor casing. The end portions 8,- ofthe bars are bent laterally and fit the inner surface of the tunnel walland are bolted or otherwise secured thereto.

The blower draws the air from the enclosure or space to be heated, andpresses the air forwardly through the tunnel and the heating throattherein and discharges the superheated air from the front end of thetunnel. I find that the elongated casing that provides a long internallyheated air draft tunnel, more quickly circulates the blower forcedsuperheated air throughout such enclosure or space to raise thetemperature thereof, than where a mere ring or short casing is employed,and furthermore the blower motorv is protected from the high temperatureof the casing ring and its enclosed heating coil by the provision of theair draft tunneL- The air pressed forward by the blower is somewhatchoked 'by the hot rear wall 4 ,of the tunnel throat (formed by" thecoil casing ring) and-said air expands withinthe forwardly flaringfluted or corrugated throat along the hot wall 4, and

- the temperature therein to the point desired further expands withinthe enlarged end of the tunnel in advance of front casing ring wall 4.

The air is efficiently heated and full advantage is taken of the hightemperature of the heating coil while said coil is rotected and is notcooled down by direct contact with the air blast.

Furthermore, if the coil becomes broken or needs repair or replacing,the radiating coil casin ring can, be readily released and removed Iromthe tunnel casing, therebyrendering the. coil accessible for repair andrenewa The blower and heated tunnel are designed to more or less rapidlycirculate the entire body of air, in the space or enclosure to beheated, through the tunnel to take up the heat generated within thetunnel, and the air draft tunnel promotes the desired rapid circulationof this hot air throughout such space or enclosure to quickly raise andthus maintain the same.

It is evident that various changes, modifications and variations mightbe resorted to without departing from the spirit and scope of myinvention and hence I do not wish to limit myself to the exactdisclosures hereof.

What I claim is 1. An electric heating machine. comprising an open endair tunnel having means for forcing air forwardly therethrough, saidtunnel having an annular internal air heating throat with heat radiatingsurfaces exposed. around the tunnel bore and electrical heating meanswithin and enclosed by said throat.

2. An air draft tunnel having a forwardly propelling air blower and anannular internal heat radiating throat within its 8.11 outlet portionprovided with and enclosing an electric heating coil.

"3. An air tunnel having a blower in its inlet end, and an annularinternal heat radiating throat remote from the blower and provided withand enclosing an electric heating coil, said throat having a forwardlyflaring bore.

4. 11 air tun-nel having a blower in its air inlet end, and an annularinternal heat radiating throat within its air outlet portion providedwith and enclosin an electric heating coil, said throat having aforwardly flaring bore with a corrugated radiating surface. I v

5. An air tunnel havin a blower and an annular internal heat rafiatingthroat provided with and enclosing an electric heating coil, the rearportion of said throat forming an annular bafiie within the tunnel bore.

'6. An air tunnel having a blower at its within said casing andsurrounding the tunnel bore, and a hollow ring within the casing formingheat radiati surfaces surrounding'the tunnel bore an exposed to the airtherein, said heating element being arranged within said ring andenclosed thereby.

8. In combination, a casing forming an air circulating tunnel, anelectric blower for propelling the air through said tunnel andcirculating the same throughout a room or the like, the front portion ofsaid tunnel being of enlarged internal diameter, a hollow metal ring setin said enlarged portion providing heat radiatin and air contactingsurfaces surrounding tfie tunnel bore, and electric resistancering-heating means enclosed within said ring.

9. In combination, a casing forming an open end air circulatin tunnel, arotary electric blower for circu ating air through said tunnel, a hollowmetal rin set in said casing and providing heat ra iating surfacessurrounding the tunnel bore and exposed to the air therein, saidring'providmg an internal annular chamber, an annular electricresistance heating c011 enclosed [within said chamber for heating thesame and said ring, and insulatin blocks within said ring supportingsaid coil from contact with the ring.

10. In combination, a vitrified ceramic material hollow casing formingan open end air circulating tunnel, a rotary air. forcing electric'blower mounted in said tunnel, a

mounted in said tunnel and.

hollow rin providing ieat radiating surfaces around the tunnel bore forheating the air therein, and a red glow electric resistance coilenclosed within said ring for heating the same.

11. In combination, a hollow casing formin an air circulating tunnelopen at both on s, clamp' bars arranged within the tunnel bore an havingtransverse clampin bolts, an electric motor arranged an clamped betweensaid bars and provided and driving a blower for forcing air through saidtunnel, and electric resistance heating means within said tunnelsurroundin the bore thereof to heat the air therein. igned atWashington, D. 0., this 4th day of October, 1923.

LEO SIMMONS.

